Lubricants



Patented June 9, .1936

STATES PATENT OFFICE LUBRICANTS tion of Delaware No Drawing. Applicationch 11 1933, Serial N0. 669,441

of, an unsatisfactory product-is often obtained due to the poor physicalappearance, darkened color, and the tendency toward sludge deposition ofthe, finished product.

'An important object of the present invention is to provide a simple andpractical manner of intrjoducing the desired amount of sulfurinto any Animportant object of the invention is to produce a high gradesulfur-containing lubricant which is stable, and free fromsludge-forming tendencies.

Another object of the invention is to produce a high grade sulfurcutting oil free from sludge and light in color.

A further object of the present invention is to provide an improvedmethod. of introducing sulfur into lubricants, such as minerallubrieating oils, by the use of cyclic unsaturated compounds orcompounds of the nature of pine oil, such as terpenes, terpineols, pineoil, pine tars, etc. K v

The incorporation of sulfur into mineral oils through the agency ofterpene compounds has been known heretofore and according to the priorart, so far as I am aware, this has been done by heating the terpenesand, sulfur under atmospheric pressure to dissolve sulfur in the terpeneto form a sulfur base which is then admixed with the lubricating oil.The sulfur base thus prepared is apparently a solution 'of sulfur in theterpene, stable only at higher temperatures 45 and on cooling to roomtemperatures the sulfur will settle from a concentrated solutionthereoi; but, when the base is mixed with a mineral oil in smallamounts, the terpene acts sumciently as a solvent-aid to eiiect solutionof the sulfur in 50 the resulting mixture of base. and lubricating oil.Sulfurized oils, however, prepared according to the above method, havethe disadvantage of be ing relatively unstable due to the ireesulfurcon'-, tent and the tendency, particularly at low temtures or inservice, to precipitate free sulfur or sludge unless large amounts ofterpenes are used.

In accordance with the present invention instead of incorporating thesulfur into theterpenetype of compound under atmospheric pressure I 5maintain a substantial superatmospheric' pres-- sureon the terpene andsulfur during the sulfurizing operation. I'have found that bymaintaining a superatmospheric pressure on the terpene and sulfurundergoing reaction, much higher tem- 1o peratures, even above theboiling point of the sulfur or terpene, may be employed, andthe time ofdigestion regulated to any time desiredwith out substantial loss of thereagents. It has been found also that a much improved product may 15 beobtained, according: to my invention, in that the sulfur apparentlyexists essentially in a chemically combined state, and accordingly largev quantities thereof may be combined with terpenes in a highly stableform. f The sulfur base so pre;

pared may be blended in a concentrated form and in any proportions witha mineral oil to give a sulfur-containing oil which is of good physicalappearance, color, and highly stable.

More particularly, according to the invention, a suitable unsaturatedcyclic compound such as terpene hydrocarbons or their derivatives, forexample, terpenes, terpineols, pin'e tars, etc, are reacted with sulfur.Pine oil.or a material of that nature is particularly suitable and Iprefer to use,- especially for themanufacture of light colored 'cuttingoils, a light pine oil, such as steam distilled Yarmor pine oil, havingan iodine value of around 100-125. The pine oil is mixed with about5-30% of sulfur and the mixture heated to a temperature in the region of300- 500" Enter about 1-5 hours under a superatmos-, pheric pressure ofaround -500 lbs. per sq. in. For a light pine oil I have found that theoptimum conditions are a temperature of about 400 F., a digestion periodof about 1-2 hours and a superatmospheric pressure of around 100-150lbs. per sq. in. It will be understood, of course, that 'theseconditions may vary with different oils but in any'case I prefer to usea temperature of at least 300 F. and a superatmospheric pressure of 50lbs. per sq. in. or more.

The pressure may be convenientlyagenerated by merely confining thevapors evolved. It has been found that a copious evolution of hydrogensul= flde occurs and by confining the gases and vaporsa self-generatedpressure of as much as 425 lbs., or more maybe obtained at temperaturesaround 400 F., and even higherpressures are possible at more elevatedtemperatures. In case insufllcient pressure is generated, an extraneousgas pressure, say of natural gas, hydrogen sulfide, or; nitrogen, may beapplied. I I

The pine oil sulfur base,

in all proportions and having a sulfur content ranging from 525% orover. It may be admixed with the desired lubricanti'n suitableproportions.

' For-a cutting oil I prefer to use a quantity sufficient toprovide from-l-% or more of sulfur I in the resulting mixture.

In case thesulfur base has an objectionable odor, for instancedue todissolved hydrogen'sulj fide, a vacuum may be applied to the oil or agas such as airbubbled therethrough to carry out the volatile materialsof bad odor. The'objectionable odor may also be removed, if desired,insubstantially the same manner after the sulfur base has;

I been blended with the lubricating oil. v I

The invention will now be described in connection with thepracticalapplication thereof to the heated with 101105.101 powdered sulfur inajflre-' preparation of a sulfur cutting oil; although the invention isnot limited thereto.

. Thirty pounds of steam distilled Yarmor pine oil having an iodinevalue of 110, an A. P. I. grave ity of 195 and a sulfur content of 0.11%were heated pressure kettle at 400 F. for 2 hours.

Gases and vapors were released sufficiently to 'maintain a gaugepressure of about; 100 lbs. per

, sq. in. The materialswere found to be completely present.

reacted and neither free sulfur nor sludge was I The, resulting productwas reddish brownin color, clear, and tested22.1% sulfur and I 1.? A. P.I. gravity. Onepart of the resulting sulfurbase was blended at roomtemperatures with 7 three parts of a pale lubricating oil having a Say-'Y bolt viscosity of'70 seconds at 100 F. The blend A tested 5.77% sulfurand waslight redincolor clear. free from sludge, exhibited extremepressure lubrication characteristics and proved highly satisfactory asacutting oil. 7

Instead of viscosity pale oil other pale oils thus prepared, is a brightreddish oil, misciblewith hydrocarbon oils theinvention, I I

made withoutdeparting from the spirit and scope 20 I 1 from -200 secondsSaybolt universal at 100 F. may be used for preparing cutting, Oils. Itis 1 also contemplated that the sulfur may be added during the digestionoperation matter the oil has reached a'reaction temperature instead of Ijfirst mixing the oil and sulfur and then heating the. mixture.

While the above described specific, embodiment I of the invention has todo with cutting-oils the invention is by no means so limited. Itis0011-.

templated that heavier oils, such as motor oils or I gear lubricantswith viscosities ranging from 200 seconds at 100 F. to 250 seconds at210? F. Saybolt universal maybe sulfuriz ed by my method.

also find valu+ ,15'

In some cases the invention may able application for the incorporationofsulfur into greases. I

Obviou'slymany modiflcations'and variations of as hereinbefore setforth, maybe thereof, and therfore only such limitations should beimposed as are indicated. in the, ap-

pended claims.

Iclaimz.

y ,1'. A sulfur base, soluble in hydrocarbon oils, 25 consistingessentially latter-present in an and 25% and incorporated in theoilundersuperof pineoil and sulfur, the amount ranging between 5atmospheric pressure, said base having an 1121- 1 proved odor andprecipitating less sulfur on storage and on cooling than abase-containing sulfur incorporated therein under atmospheric pres-jisure in sulfur base, soluble in mineral lubricatin under Isuperatmospherio Us KAUFMAN.

